The "basic science" objective of this project is to begin to investigate how the possible motivational underpinnings of the Sensation Seeking personality trait might influence the processing of messages about substance use. A great deal of research has linked sensation seeking to drug use and abuse. The research proposed here begins to investigate a proposed relationship between resting levels of activation in a person's appetitive and aversive motivational systems and sensation seeking. This research will attempt to measure underlying activation in the motivational systems as an individual difference variable. These measures will then be used to sort people into different motivational types (e.g. high appetitive activation & high aversive activation, high appetitive activation & low aversive activation, etc.). Relationships among substance use, sensation seeking, appetitive and aversive activation, and motivational type will be examined. Finally, this research will investigate whether resting level of activation in the appetitive and aversive motivational systems mediates cognitive, attitudinal, and emotional responses to prevention messages which differ in terms of production pacing, arousing content, and valence of the message appeal.